Working with IGES files in Solid Edge

Initial Graphic Exchange (IGES) is a neutral file format for storing graphic data to be exchanged between graphic systems. Solid Edge supports version 5.3 of the IGES specification.

The IGES file format is a formatted ASCII file with a fixed record length of 80 characters. The file contains five sections. Column 73 of the file contains a letter to identify the section. Columns 74 - 80 contain the sequence number within the section.

Section

Identification Letter

Description

Start

S

Contains information for the receiving system in free ASCII text format.

Global

G

Contains global information, such as units, IGES version, and file name, about the sending system.

Directory Entry

D

Contains two lines describing a single entity in the folder sections containing up to 20 fields separated by commas.

Parameter Data

P

Contains parameter information, such as coordinates and text strings, for the entity.

Terminate

T

Contains information on how many lines are in the different sections. This is used to determine if you have a complete IGES file.

Japan Automobile Manufacturers Association (JAMA)

Japan Automobile Manufacturers Association (JAMA) IGES is a subset of IGES. Therefore any receiving system, including Solid Edge, will read JAMA IGES files.

While IGES is large and broad in nature, JAMA was designed to be a trimmed back, more robust version of IGES. Because it is a subset, it does not support some entity types, such as type 120 Surface of Revolution. This means that almost all surface types in JAMA will be spline surfaces.

Getting the Best IGES Export from Solid Edge Results

Before you save Solid Edge files to IGES, you should become familiar with the capabilities of the receiving system. Review a list of supported entities from the system's translator documentation, such as a user's manual. Check to see if there are specific entities that the receiving translator has difficulties reading.

When you create an IGES file, be sure to avoid entities the receiving system cannot handle. Set options to customize your IGES file for specific entities based on the capabilities of the receiving system. For example, you may find that the receiving system does not support the Manifold Solid Brep entity type 186. Therefore, it is necessary to output the Solid Edge model as trim surfaces.

After you save a file to IGES, review the resulting IGES output and the data in the log file. Compare the options used in the translation to the options you intended to set.

Open the resulting IGES file in Solid Edge to see if it contains what you expect. Request a report, such as a copy of the log file, from the receiving system.

Record the options and maintain these records. They will be useful in future translations.

Getting the Best IGES Import into Solid Edge Results

It is important that you get the best possible results when you import IGES files into Solid Edge. To do this, the IGES file must be clean and free from discrepancies of the sending system.

To ensure that the IGES file is valid for the translation, use proper options when you transmit the file between systems or from differing media. If the sending system is able to check or validate its geometry for errors, do so. Fix any existing problems before translating the file.

You should clean up the file you want to translate before conversion. Delete items such as associated drawings, annotations, or construction geometry. Keep only the information that you intend to translate.

When setting the options to export to Solid Edge, the following IGES entities should be exported:

If the above entity options are not available, set the export option to Unigraphics if available.

Review your resulting output

Once the file is translated, be sure to check the output. Review the data in the log file. Check the options you selected for translation and make sure the results are correct. If you find errors, investigate the cause.

Save the translated Solid Edge file in IGES (.IGS) format and check the resulting file to see if it contains what you expect.

Record the options and maintain these records to use in future translations.

What to do if you find errors

If you discover errors in your translation, you should analyze the problem and determine where the problem occurred. When analyzing the problem, you should consider:

Error messages in the IGES log file

If the log file contains error messages, try to remove the feature causing the problem. After removing the feature, try to resave the file in IGES format. If this solves the problem, investigate the geometry in the problem feature. Consider using another method to construct the feature. If no other creation methods exist and the feature is not necessary for the translation, remove it. As a general rule, the problem must be resolved before you can continue with the translation.

Errors in the loop test

Although this is not always a conclusive test, it does serve as a good indicator that you are on the right track. If this process fails to read the file correctly, investigate the failed features. Determine if the failed features are necessary for the translation, and if they can be created with less complexity.

Error message in the receiving system

The receiving system may complain or list entities that are not supported. Use different options to change unsupported entities to other corresponding entities. The receiving system may also report errors and record numbers of the unsupported entities in the IGES file. These record numbers may be useful when you research the problem.

Geometry that fails to stitch

Most CAD systems do not support the IGES definition of a Manifold Solid Brep Object (IGES Type 186). Therefore, they must rely on translating solid models as Trim Surfaces Type 144. Trim surfaces are simply a surface and a trimming curve. During IGES to Solid Edge translation, these surfaces are stitched, and the surface normals are then oriented to form a solid.

Stitching is performed on the entire collection of trim surfaces in the IGES file. Several passes at stitching are attempted based on a starting and ending tolerance and a number of attempts value. The following are examples of how these tolerances are defined.

Start At:1e-006 meters 
End At: 0.001 meters
Number of Attempts: 10

Beginning with the starting stitch tolerance, Solid Edge attempts to sew the collection of trim surfaces. If Solid Edge cannot create a valid solid body, it makes a second attempt by adjusting the stitch tolerance by the predetermined tolerance value. This process continues until a valid solid body is created or the ending stitch tolerance is achieved.

Geometry that fails to stitch is usually related to tolerances, poor surface quality, or an open surface definition.

Geometry that fails to stitch becomes construction geometry. Because it is construction geometry, you cannot add new features or remove existing features. However, this does not mean that you cannot use the translated data in Solid Edge.

You can use construction geometry in the following Solid Edge commands:

Thicken command

If the translated geometry forms a single sheet, you can use the Thicken command to apply a uniform thickness to the sheet and create a solid from the construction geometry.

Save as Flat command

If the geometry represents a sheet metal part, such as a flange or tab, you can use the Save as Flat command in the Sheet Metal environment to flattened and convert it to a solid. You can use the Save as Flat dialog box to save the geometry as a sheet metal (.PSM) file. Solid Edge converts the construction geometry to the flat state of a solid and creates a sheet metal file. The bends are added automatically, and you can use the Rebend command to fold the file into a 3-D sheet metal model. You can then add sheet metal features like flanges and dimples to the converted model.

Drawing View Wizard command

You can use the Drawing View Wizard command to create a drawing view of the construction geometry. In most cases, you can use this geometry to create a detailed drawing.

PathFinder

You can use PathFinder to place construction geometry in an assembly just as you would use solid geometry.

Create In-place command

Perhaps your workflow only consists of building enclosures or fixtures from the imported geometry. You can use the Create In-place command to place the construction geometry in an assembly file and create a new part file. The Create In-place command allows you to use the Include command to include edges from the construction geometry to create a new part file.

Bulk translations

The seiges.exe executable, found in the Solid Edge Program folder, allows you to translate multiple IGES files for both import and export through a standalone interface. The executable is not referenced from the Solid Edge product, but it does contain options similar to the IGES Import and IGES Export Translation Wizards, except it allows you to specify a list of files to be translated.

IGES entities supported by Solid Edge

The following is a list of IGES entities that are supported by Parasolid.

IGES Entity #

Form No.

IGES Entity

Solid Edge Entity

#100

0

Circle Arc

Circle

#102

0

Composite Curve

Curve List

#104

0

Conic Arc: General

Spline Curve

#104

1

Conic Arc: Ellipse

Ellipse

#106

11

Copious Data: 2D Path

Curve List

#106

12

Copious Data: 3D Path

Curve List

#106

63

Copious Data: Closed 2D Curve

Curve List

#108

1

*Plane Entity: Bounded Plane

Plane

#110

0

Line

Line

#116

0

Point

Point

#118

1

Ruled Surface

Spline

#120

0

Surface of Revolution

Spun Surface

#122

0

Tabulated Cylinder

Swept Surface

#123

0

Direction

Vector

#124

0

Transformation

Transf

#126

0

Rational B-Spline Curve

Spcurve

#128

0

Rational B-Spline Curve

Spline

#130

0

Offset Curve

Curve

#140

0

Offset Surface

Surface

#141

0

Boundary Entity

Loop

#142

0

Curve on Parametric Surface

Loop

#143

0

Bounded Surface

Face

#144

0

Trimmed Surface

Face

#186

0

MSBO

Solid

#190

0

Plane Surface

Plane

#192

0

Right Circular Cylindrical Surface

Cylinder

#194

0

Right Circular Conical Surface

Cone

#196

0

Spherical Surface

Sphere

#198

0

Toroidal Surface

Torus

#308

0

Subfigure Definition Entity

Solid

#402

1,7

*Associative Instance Entity

#408

0

Subfigure Instance Entity

Solid

#502

1

Vertex List

Vertex

#504

1

Edge List

Edge

#508

1

Loop

Loop

#510

1

Face

Face

#514

1

Shell

Shell

*Only for IGES Read

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